Apparatus for conveying and depositing sheets moving from cross cutters or other paper handling machines



Aug. 15, 1967 SCHONMEIER 3,336,028

APPARATUS FOR CONVEYING AND DEPOSITING SHEETS MOVING FROM CROSS HINESCUTTERS OR OTHER PAPER HANDLING MAC Filed July 12, 1965 United StatesPatent 3,336,028 APPARATUS FOR CONVEYING AND DEPOSITENG SHEETS MOVINGFROM CRGSS CUTTERS OR OTHER PAPER HANDLING MACHINES Herbert Schonmeier,Dusseldorf-Benrath, Germany, assignor to Jagenberg-Werlte AG,Dusseldorf, Germany Filed July 12, 1965, Ser. No. 471,218 Claimspriority, application Germany, July 30, 1964, J 26,303 7 Claims. (Cl.27174) ABSTRACT OF THE DISCLUSURE An apparatus for conveying anddepositing sheets of paper cut from a moving web in an overlappedrelationship including a plurality of conveyor belts arranged in seriesand movable at stepwise reduced speeds. One of the conveyor belts isprovided with an endless perforated surface and such belt passes over aroll having a perforated periphery. The roll is connected to a suctionsource and is adapted to apply suction to the rear end of a movingsheet. A control means is located within the roll in a limitedcircumferential zone for a timed suction effect.

A transfer table is positioned in advance of the roll and means areprovided for directing compressed air from the forward end of the tablein the direction of a sheet and for applying suction to a sheet at therearward end of the table, respectively.

The present invention relates to an apparatus for conveying anddepositing sheets moving from cross cutters or other paper handlingmachines and more particularly to an apparatus wherein, for the purposeof reducing the speed of movement and for simultaneously effecting anoverlapping of the sheets, a plurality of conveyor belts arranged inseries one behind another and operated at stepwise reduced speed isprovided.

In German patent application No. I. 15,630, it is proposed to provide inthe zone of a conveyor belt a suction braking means for initiating anoverlapping of successive sheets or increasing an overlapping alreadyinitiated. The braking action is effected on that end of the sheetlocated rearwardly in the direction of movement and displaces such endout of the zone of travel of the forward end of the succeeding sheet.The effective upper side of the suction braking means is locatedsomewhat lower than the preceding conveyor belt. In this arrangement,the confinement, so to speak, of the braking action to the rear end ofthe sheet is of special significance as there is caused a stretching ofthe sheet thereby avoiding wrinkling of the sheet.

At high operating speeds and particularly when processing thin papers itis essential if trouble is to be avoided to take steps for assuring thatthe suction braking is effected in a timed fashion dependent on thesheet sequence and upon the rearward ends of the sheets. In the Germanapplication mentioned, due to the required size of the suction brakingmeans or box, a timed execution of a suction action occurring in a rapidsequence would meet diificulties. In a situation where the suctionopenings are closed and opened by mechanical means, the difficultieswould be caused by the high timing sequence which necessitates a rapidback and forth movement of a covering component. Moreover, in the caseof a control activated between the suction braking means and a suctionproducing device, other problems arise as the large volume of thesuction braking means and conduits does not ensure the required rapidbuild up and drop of a vacuum.

To eliminate these difl'iculties, the present invention emice ploys, inlieu of stationary suction braking means or suction box, a rotatableroll or drum having perforations in its wall about which is guided aconveyor belt having perforations therein and within the roll is locatedcontrol means operably coupled with vacuum producing means which controlmeans in timed sequence and within a limited circumferential zone allowsthe suction to become effective.

More specifically, a rotatable conduit is arranged within the perforatedroll and is provided with one or more slots disposed transversely to thedirection of movement. A stationary conduit is located within therotatable conduit and is formed with a slot positioned in the effectivezone of the vacuum and the rotational speed of the rotatable conduit isso adjusted that the suction effect is only applied to the rearward endof a sheet.

In order to bridge the gap between the belt conveyor passing about theperforated roll and the preceding or belt conveyor immediately inadvance thereof, a transfer table is located ahead of the perforatedroll with respect to the direction of movement of the sheets and is soconstructed that in its forward and rearward areas, pressure and vacuum,respectively, become operative with the vacuum be ing produced by theperforated roll. Furthermore, the upper side or surface of the transfertable is located slight ly beneath the uppermost point of the perforatedroll and to improve the suction action on the upper flight of the beltconveyor moving about the perforated roll, the perforations of theconveyor are in the nature of elongated slots extending in the directionof travel of the belt and by virtue thereof the covering zone betweenthe perforations of the roll and the slots of the conveyor belt issubstantially augmented.

Further important objects and advantages of the invention will becomemore fully apparent to persons skilled in the art from the followingdetailed specification and drawings, in which drawings:

FIG. 1 is a diagrammatic view illustrating the conveying and depositingapparatus coupled in series with a cross cutter assembly,

FIG. 2 is a view in vertical cross section and on an enlarged scale ofthe suction braking means of the invention defined by a suction roll ordrum, and

FIG. 3 is a fragmentary top plan view of the perforated conveyor beltpassing about the suction roll.

Referring to FIG. 1, it will be noted that a paper web 1 emanating froma source of supply (not disclosed) is grasped and moved by feed rollers2 towards a cross cutting assembly 3 constituted by upper and lowerrotatable knives. Sheets 4 which are severed from the web by the cuttingassembly 3 are moved over an immediate support 5 to the entrance area ofupper and lower endless conveyor belts 6 and 7 which move at the samespeed and receive the sheets between the lower flight of the conveyor 6and the upper flight of the conveyor 7. It can be seen that the lowerbelt 7 is of lesser length than the belt 6 and a further conveyor belt 8is located beyond the lower belt 7 with its upper flight 8a beingdisposed slightly below upper flight 7a of the belt 7. The conveyor belt8 which moves at a lesser speed than the conveyor belts 6 and 7 isformed with a plurality of perforations 9 and, as best illustrated inFIG. 3, the perforations are in the form of elongated slots which extendin the direction of movement of the belt 8.

The belt 8 is trained about forward and rearward rolls or drums 10 and19a, respectively. The forward roll 10 is provided with apertures 11 inthe wall thereof (FIG. 2) for constituting a suction roll and is adaptedto be connected to a vacuum producing means (not shown). A rotatableconduit 12 is mounted within the roll 10 and, as illustrated, the wallof the conduit 12 is formed with two substantially diametrically opposedslots 13 with the slots 13 extending in the direction of the rotationalaxis of the roll. A fixed or stationary conduit 14 is located within therotatable conduit 12 and is provided with a slot 15 which extends in thedirection of the rotational axis of the roll 10.

As perhaps best disclosed in FIG. 2, a transfer. table 16 is mounted inthe hiatus between the exit end of the lower conveyor belt 7 and theentrance end of the conveyor belt 8. The upper side or surface of thetable 16 is positioned slightly below the uppermost point of the roll ordrum 11 and the end of the table facing the conveyor 7 is formed withone or more blast nozzles 17. The area or end of the table 16 adjacentthe conveyor belt 8 is provided with a plurality of bores 18 whichextend angularly in a direction toward the movement of the sheets.

While the operation of the present apparatus is believed readilyapparent from the foregoing, it may be summarized as follows:

The vacuum constantly prevailing within the stationary conduit 14becomes effective in a limited circumferential zone of the conveyor belt8 when the slot 15 of the conduit 14 registers with one of the slots 13of the rotatable conduit 12 with such zone extending from the rear ofthe transfer table 16 to the end of the embracernent of the roll 10 bythe conveyor belt 8.

The rotational speed of the conduit 13 is so selected that the vacuumbecomes operative in a timed sequence and only when the rearward end ofa sheet 4 is located in the Zone of the transfer table 16 and the roll10. As previously pointed out, since the speed of the belt 8 is lessthan that of the conveyor belt 7, the sheet 4-, due to the suctionbraking action imposed on the rearward end of the sheet, is caused tomove with the lower speed of the belt 8. By reason of the foregoing, thefollowing sheet which is moved forward by the higher speed of the belt 7displaces itself over the preceding sheet in the direction of traveland, dependent upon the dilference in speeds respecting the conveyorbelts 7 and 8, a greater or lesser overlapping of the sheets isaccomplished.

In view of the fact that the uppermost point of the roll 10, the lowerflight of the conveyor belt 8 and the upper surface of the table 16 arepositioned beneath the conveying plane of the next succeeding sheet, theforward end of the succeeding sheet is prevented from contacting therearward end of the preceding sheet. Moreover, in the forward zone ofthe transfer table 16 there is rendered effective a compressed fluidstream which is directed in a substantially upward direction forstriking the lower face of the advancing sheet. The aforementioned fluidstream maintains the forward end of the sheet in the higher conveyingplane until a substantial overlapping is achieved. With furtheradvancing movement of the conveyor belt 8, the sheets thus overlappedare deposited via injection means into a stack holder 19.

The invention is not to be confined to any strict conformity to theshowings in the drawings but changes or modifications may be madetherein so long as such changes or modifications mark no materialdeparture from the spirit and scope of the appended claims.

What is claimed is:

1. In an apparatus for conveying and depositing sheets of paper severedfrom a moving web in an overlapped relationship, a plurality of conveyorbelts arranged in series and movable at stepwise reduced speeds, one ofthe conveyor belts being provided with an endless perforated surface, aroll having a perforated periphery about which said one conveyor beltmoves, means for connecting said roll to a suction source for applyingsuction to the rear end of a moving sheet and control means locatedwithin said roll in a limited circumferential zone for a timed suctioneffect.

2. The apparatus as claimed in claim 1 wherein the control meansincludes a conduit rotatably mounted within the roll, said conduithaving at least one slot disposed transversely to the direction ofmovement of said one conveyor belt, and a stationary conduit locatedwithin the rotatably mounted conduit provided with a slot disposed inthe effective zone of the suction.

3. The apparatus as claimed in claim 2 in which the speed of therotatably mounted conduit is so selected that a suction is applied onlyto the rear end of a sheet.

4. The apparatus as claimed in claim 1 including a transfer table havingforward and rearward ends positioned in advance of the roll, means fordirecting compressed air from the forward end of the table in thedirection of a sheet and means for applying suction to a sheet at therearward end of the table.

5. The apparatus as claimed in claim 4, in which the means for applyingsuction at the rearward end of the table is effected by the roll.

6. The apparatus as claimed in claim 5 in which said transfer table isprovided with an upper surface located slightly lower than the uppermostpoint of the roll.

7. The apparatus as claimed in claim 1 in which the perforations in saidone conveyor belt are defined by elongated slots extending in thedirection of movement of said one conveyor belt.

References Cited UNITED STATES PATENTS 2,065,178 12/1936 Federwitz etal. 271-74 X 3,178,174 4/1965 Schneider 27174 X M. HENSON WOOD, JR.,Primary Examiner.

ALLEN N. KNOWLES, Examiner.

1. IN AN APPARATUS FOR CONVEYING AND DEPOSITING SHEETS OF PAPER SEVEREDFROM A MOVING WEB IN AN OVERLAPPED RELATIONSHIP, A PLURALITY OF CONVEYORBELTS ARRANGED IN SERIES AND MOVABLE AT STEPWISE REDUCED SPEEDS, ONE OFTHE CONVEYOR BELTS BEING PROVIDED WITH AN ENDLESS PERFORATED SURFACE, AROLL HAVING A PERFORATED PERIPHERY ABOUT WHICH SAID ONE CONVEYOR BELTMOVES, MEANS FOR CONNECTING SAID